Nice bike SSD!
Unfortunately I cant give a definitive shelf life; it's dependant on loads of factors such as fuel manufacturing process, storage conditions, temperature and humidity variations, etc etc.
Fuel stabilisers are generally oxygen stability improvers. These surpresses the formation of corrosive peroxides arising from exposure to oxygen. Unfortunately they have no effect on the loss of volatile components through evaporation. A simple (and cheaper) alternative to stabilisers is to keep your tank full; this would reduce the surface area to fuel volume ratio. This also helps with the loss of volatiles, and would reduce the quantity of water condensing from the air above the fuel within the tank.
Another factor on shelf life for leaded fuels such as 100LL or 4 star would be the loss of lead content. The lead, which is added to gasoline in the form of tetra-ethyl lead, will coat any metallic surface over time, and in prolonged storage the concentration remaining in the fuel may fall below engine-specified limits. This could ****** your valves and cylinders, and really ruin your day.